The present invention relates to power distribution units and providing power from a bus within the power distribution unit. More particularly, the present invention relates to providing protection and alarming for the bus within the power distribution unit.
Power distribution units generally provide current to downstream devices operating at a given voltage. A bus is included in the power distribution unit and acts as a voltage node that provides the current to the devices. The current that is provided to each individual device generally falls within an acceptable range. However, one or more downstream devices may draw more current than normal due to a heavier than normal load or due to a device malfunction. For purposes of protecting both the power distribution unit and the downstream device, it is desirable to block current from the power distribution unit to the downstream device when the current drawn by the device exceeds a threshold amount.
Limiting the current to the downstream device is often done by including a fuse in each line leading to each device from the bus. The fuse often provides an alarm voltage so that when the fuse blows due to excessive current, the alarm is triggered. However, the conventional use of fuses in power distribution busses has drawbacks when multiple lines of power are being provided by the power distribution unit because the alarm circuit of conventional power distribution units indicates that a fuse is blown but does not indicate which line is blocked due to a blown fuse. Furthermore, conventional power distribution units that are configured to operate with fuses are not configured to operate with circuit breakers on some or all lines.
Circuit breakers are used by some conventional power distribution units to limit the current in each line. However, conventional power distribution units using circuit breakers suffer from the same drawbacks as those using fuses. A general alarm is generated by the alarm circuit of a conventional power distribution in response to a tripped breaker, but no indication of the particular line that is blocked is provided. Furthermore, conventional power distribution units that are configured to operate with a circuit breaker are not configured to also operate with a fuse on some or all lines.
It may be useful in some instances to have fuses on some of the lines output by the power distribution bus while having circuit breakers on other lines. Circuit breakers often have an alarming capability that functions by receiving voltage from a voltage source, such as from the alarm circuit itself. Fuses often have an alarming capability that functions by channeling voltage from the power distribution line to the alarm circuitry. Therefore, conventional power distribution units have not permitted interchanging fuses with circuit breakers.
Thus, there is a need in the art for more flexible protection and alarming capabilities for power distribution buses.
The embodiments of the present invention address the problems discussed above and others by providing a power distribution bus with flexible protection and alarming features. Various embodiments permit fuses to be mixed with circuit breakers, permit discrete alarming for each line from the bus, permit combined alarming for the lines of the bus, and/or permit selectable discrete or combined alarming.
The present invention may be viewed as a method of employing fuses and circuit breakers with a power distribution bus. The method involves inserting a fuse with an alarm connector in a first location plugged into the bus for receiving power from the power distribution bus and inserting a circuit breaker with a pair of alarm connectors in a second location plugged into the bus for receiving power from the power distribution unit. The method also involves inhibiting a response from an alarm circuit electrically linked to the first location and second location until the fuse is blown or until the circuit breaker is tripped.
The present invention may be viewed as a power distribution bus alarm circuit. The power distribution bus includes a first and a second socket, each having three alarm connections and two power connections. The bus also includes an alarm circuit connected to first and second alarm connections of the first and second sockets, with the alarm circuit being responsive to a voltage being applied from the first of the three connections of the first or second socket and being responsive to a voltage being applied across second and third connections of the first or second sockets. The bus additionally includes a voltage source electrically connected to third alarm connections of the first and second sockets. The bus also includes a fuse positioned in the first socket, with the fuse electrically interconnecting the two power connections and isolating the first alarm connection from the power connection when in a non-blown state. Additionally, the bus includes a circuit breaker positioned in the second socket, with the circuit breaker electrically interconnecting the two power connections when in a non-tripped state and electrically interconnecting the second and third alarm connections when in a tripped state.
The present invention may be viewed as another method of employing fuses and circuit breakers with a power distribution bus. The method involves inserting a fuse with an alarm connector in a first location in the bus for receiving power from the power distribution unit and inserting a circuit breaker with a pair of alarm connectors in a second location in the bus for receiving power from the power distribution unit. The method additionally involves inhibiting a response from a first alarm circuit electrically linked to the first location until the fuse is blown and inhibiting a response from a second alarm circuit electrically linked to the second location until the circuit breaker is tripped.
The present invention may be viewed as another power distribution bus alarm circuit. The bus includes a first and a second socket, with each having three alarm connections and two power connections. The bus includes a first alarm circuit connected to first and second alarm connections of the first socket, with the alarm circuit being responsive to a voltage being applied from the first of the three connections of the first socket and being responsive to a voltage being applied across second and third connections of the first socket. The bus also includes a second alarm circuit connected to first and second alarm connections of the second socket, with the alarm circuit being responsive to a voltage being applied from the first of the three connections of the second socket and being responsive to a voltage being applied across second and third connections of the second socket. The bus additionally includes a voltage source electrically connected to third alarm connections of the first and second sockets. Also, the bus includes a fuse positioned in the first socket, with the fuse electrically interconnecting the two power connections and isolating the first alarm connection from the power connection when in a non-blown state. Additionally, the bus includes a circuit breaker positioned in the second socket, with the circuit breaker electrically interconnecting the two power connections when in a non-tripped state and electrically interconnecting the second and third alarm connections when in a tripped state.
The present invention may be viewed as another method of employing fuses and circuit breakers with a power distribution bus. The method involves inserting a fuse with an alarm connector in a first location in the bus for receiving power from the power distribution unit and inserting a circuit breaker with a pair of alarm connectors in a second location in the bus for receiving power from the power distribution unit. The method also involves electrically connecting the first location to a first alarm circuit or a second alarm circuit and electrically connecting the second location to the first alarm circuit or to a third alarm circuit. Additionally, the method involves inhibiting a response from the first alarm circuit or second alarm circuit electrically linked to the first location until the fuse is blown and inhibiting a response from the first alarm circuit or third alarm circuit electrically linked to the second location until the circuit breaker is tripped.
The present invention may be viewed as another power distribution bus alarm circuit. The power distribution bus includes a first and a second socket, with each having three alarm connections and two power connections. The bus also includes a voltage source electrically connected to third alarm connections of the first and second sockets. Additionally, the bus includes a fuse positioned in the first socket, with the fuse electrically interconnecting the two power connections and isolating the first alarm connection from the power connection when in a non-blown state. The bus also includes a circuit breaker positioned in the second socket, with the circuit breaker electrically interconnecting the two power connections when in a non-tripped state and electrically interconnecting the second and third alarm connections when in a tripped state. The bus additionally includes a first conductive path extending from the first alarm connection of the first socket, with the first conductive path including a first diode that prevents current flow between the first alarm connection of the first socket and the first alarm connection of the second socket. The bus also includes a second conductive path extending from the first alarm connection of the second socket, with the second conductive path including a diode that prevents current flow between the first alarm connection of the second socket and the first alarm connection of the first socket. The bus further includes a third conductive path extending from the second alarm connection of the first socket, with the third conductive path including a diode that prevents current flow between the second alarm connection of the first socket and the second alarm connection of the second socket. The bus also includes a fourth conductive path extending from the second alarm connection of the second socket, with the fourth conductive path including a diode that prevents current flow between the second alarm connection of the second socket and the second alarm connection of the first socket.
The present invention may also be viewed as a method of employing fuses with a power distribution bus. The method involves inserting a first fuse with an alarm connector in a first location in the bus for receiving power from the power distribution unit and inserting a second fuse with an alarm connector in a second location in the bus for receiving power from the power distribution unit. The method also involves inhibiting a response from a first alarm circuit electrically linked to the first location until the first fuse is blown and inhibiting a response from a second alarm circuit electrically linked to the second location until the second fuse is blown.
The present invention may be viewed as a power distribution bus alarm circuit. The power distribution bus includes a first and a second socket, each having an alarm connection and two power connections. The bus also includes a first alarm circuit connected to the alarm connection of the first socket, with the first alarm circuit being responsive to a voltage being applied from the alarm connection of the first socket. The bus additionally includes a second alarm circuit connected to the alarm connection of the second socket, with the second alarm circuit being responsive to a voltage being applied from the alarm connection of the second socket. Also, the bus includes a first fuse positioned in the first socket, with the first fuse electrically interconnecting the two power connections and isolating the alarm connection of the first socket from the power connection when in a non-blown state. The bus also includes a second fuse positioned in the second socket, with the second fuse electrically interconnecting the two power connections isolating the alarm connection of the second socket when in a non-blown state.
The present invention may be viewed as a method of employing circuit breakers with a power distribution bus. The method involves inserting a first circuit breaker with a pair of alarm connectors in a first location in the bus for receiving power from the power distribution unit and inserting a second circuit breaker with a pair of alarm connectors in a second location in the bus for receiving power from the power distribution unit. The method further involves inhibiting a response from a first alarm circuit electrically linked to the first location until the first circuit breaker is tripped and inhibiting a response from a second alarm circuit electrically linked to the second location until the second circuit breaker is tripped.
The present invention may be viewed as another power distribution bus alarm circuit. The bus includes a first and a second socket, each having two alarm connections and two power connections. The bus also includes a first alarm circuit connected to first and second alarm connections of the first socket, with the alarm circuit being responsive to a voltage being applied across the two connections of the first socket. The bus additionally includes a second alarm circuit connected to first and second alarm connections of the second socket, with the alarm circuit being responsive to a voltage being applied across the two connections of the second socket. The bus also includes a voltage source electrically connected to one of the two connections of the first and second sockets. The bus includes a first circuit breaker positioned in the first socket, with the first circuit breaker electrically interconnecting the two power connections when in a non-tripped state and electrically interconnecting the two alarm connections when in a non-blown state. The bus also includes a second circuit breaker positioned in the second socket, with the second circuit breaker electrically interconnecting the two power connections when in a non-tripped state and electrically interconnecting the two alarm connections when in a tripped state.
The present invention may be viewed as another method of employing fuses with a power distribution bus. The method involves inserting a first fuse with an alarm connector in a first location in the bus for receiving power from the power distribution unit and inserting a second fuse with an alarm connector in a second location in the bus for receiving power from the power distribution unit. The method further involves electrically connecting the first location to a first alarm circuit or a second alarm circuit and electrically connecting the second location to the first alarm circuit or to a third alarm circuit. Additionally, the method involves inhibiting a response from the first alarm circuit or second alarm circuit electrically linked to the first location until the first fuse is blown and inhibiting a response from the first alarm circuit or third alarm circuit electrically linked to the second location until the second fuse is blown.
The present invention may be viewed as another power distribution bus alarm circuit. The bus includes a first and a second socket, with each having an alarm connection and two power connections. The bus also includes a first fuse positioned in the first socket, with the first fuse electrically interconnecting the two power connections and isolating the alarm connection of the first socket from the power connection when in a non-blown state. The bus includes a second fuse positioned in the second socket, with the second fuse electrically interconnecting the two power connections and isolating the alarm connection of the second socket from the power connection when in a non-blown state. The bus includes a first conductive path extending from the alarm connection of the first socket and a second conductive path extending from the alarm connection of the second socket. The bus also includes a third conductive path extending from the alarm connection of the first socket and a fourth conductive path extending from the alarm connection of the second socket.
The present invention may be viewed as another method of employing circuit breakers with a power distribution bus. The method involves inserting a first circuit breaker with a pair of alarm connectors in a first location in the bus for receiving power from the power distribution unit and inserting a second circuit breaker with a pair of alarm connectors in a second location in the bus for receiving power from the power distribution unit. The method also involves electrically connecting the first location to a first alarm circuit or a second alarm circuit and electrically connecting the second location to the first alarm circuit or to a third alarm circuit. The method additionally involves inhibiting a response from the first alarm circuit or second alarm circuit electrically linked to the first location until the first circuit breaker is tripped. Also, the method involves inhibiting a response from the first alarm circuit or third alarm circuit electrically linked to the second location until the second circuit breaker is tripped.
The present invention may be viewed as another power distribution bus alarm circuit. The bus includes a first and a second socket, with each having two alarm connections and two power connections. The bus also includes a voltage source electrically connected to one of the alarm connections of the first and second sockets. The bus includes a first circuit breaker positioned in the first socket, with the first circuit breaker electrically interconnecting the two power connections when in a non-tripped state and electrically interconnecting the two alarm connections when in a tripped state. The bus also includes a second circuit breaker positioned in the second socket, with the second circuit breaker electrically interconnecting the two power connections when in a non-tripped state and electrically interconnecting the alarm connections when in a tripped state. The bus additionally includes a first conductive path extending from the alarm connection of the first socket not connected to the voltage source and a second conductive path extending from the alarm connection of the second socket not connected to the voltage source.